This is how to print from a laptop at Princeton, courtesy of the lovely OIT. You need to download a little print-client; from there it's easy.

The complete list of Princeton cluster printers is here. Remember that printers get overloaded in the ten minutes before each class slot (funny, that) especially during midterms and finals. This is especially true in Frist. If you can possibly print early, or wait until mid-class-slot, that might be helpful.